Sealing and/or joining of particular vascular tissue during surgery is an essential part of an operation or procedure. Sutures, staples and adhesives have been used with varying levels of success. These prior techniques and the material and equipment used fail to minimize or limit the damage to the particular tissue and most importantly do not eliminate foreign body reactions of the patient to the added material. Specifically, the reaction of the patient's body is normally to surround the foreign body, i.e. added scar tissue, with barrier cells to thereby isolate the foreign matter from the normal cells within the patient. Consequently, the scar or evidence of the trauma is increased in size. The added material increases the cost of any surgical operation or procedure and post surgical concerns and healing.
Vascular tissue sealing and/or joining is important to the minimization of and/or elimination of bleeding or to the reconnection of tissue structures after surgical removal of undesirable organs or growths. Electrosurgery has been used to cut and coagulate tissue but the control needed to cleanly seal and/or join cut tissue and coagulate the bleeders has been lacking particularly in highly vascularized tissue, i.e. the particular patient tissue of interest and concern herein. Specifically, various approaches to coagulation, fulguration, cauterization for forming minimal and or flexible eschar over the bleeders have been tried. Different high frequency waveforms for coagulation by electrosurgical energy, argon gas enhanced coagulation and non sticking electrosurgical electrodes have been designed manufactured and sold with varying degrees of success at reducing healing time and the amount of evidence of surgical intrusion. All of the foregoing increases cost and complexity of surgical healing.
U.S. Pat. 4,043,342 has electrosurgical implements with sesquipolar electrode structures with active and return electrodes supported by insulated connectors respectively spring biased.
WO 9313719 has an electrosurgical instrument including a support structure with two electrodes interconnected with it to allow relative motion there between. A biasing device, such as a spring, urges the current return electrode into contact with tissue when the active electrode is positioned for surgery. The return electrode is longitudinally and laterally movable relative to the active electrode. A signal source provides a tissue cutting signal and a coagulation signal. The current return electrode has a tissue contact surface which defines a planar interface with the tissue during surgery. The active electrode is transversely movable relative to the interface. It increases contact surface to reduce likelihood of tissue damage and to easily control cutting depth. U.S. Pat. No. 5,047,027 has a bipolar electrosurgical instrument designed for resecting tumorous growths from the esophagus bladder or other internal organ wherein the site of the tumor is reached by way of an endoscope. The cutter is dimensioned to fit down the central lumen of the endoscope. An elongated flexible tube has a conductive helical spring cantilevered from the distal end of the tube, forming a return electrode and conductive wire hoop spaced a predetermined gap distance from the distalmost convolution of the helical spring and whose plane is perpendicular to the longitudinal axis of the flexible tube forms the active electrode.
Wires for applying a high frequency RF voltage across the electrodes extend through the lumen of the flexible tube. As the distal end portion of the instrument is dragged over the tumor to be resected, the cantilevered helical spring is laterally displaced, allowing the RF current leaving the active hoop electrode to cut through the tumorous tissue.
U.S. Pat. No. 5,007,908 has an instrument with an elongate flexible tubular member having a proximal end, a distal end and multiple lumens extending between them. Affixed to the distal end of the tube is a bullet-shaped ceramic tip member having a centrally-disposed longitudinal bore passing through the side wall of the tip member. The ceramic exterior surface of the tip member is covered with a conductive layer forming a first inactive electrode. An electrical conductor joined to that electrode surface feeds back through a lumen of the tube to its proximal end where it may be coupled to an electrosurgical generator. Also running through a lumen in the tube is another conductor which can be made to project outwardly through the opening in the top member. A hub having a spring-loaded plunger is affixed to the proximal end of the tube with the plunger joined to the wire so that when the plunger is depressed the distal end of the wire will project a short distance beyond the extremity of the tip member. By coupling this second conductor to an electrosurgical generator, it becomes the active electrode of a bipolar pair.
U.S. Pat. No. 5,290,286 has an electrosurgical instrument with a bipolar pair of conductive electrodes for the cutting of tissue in which at least one electrode is moveable in relation to the other. The electrodes are mounted relative to an insulating plug, which is secured at the distal end of a tubular member. Pressure exerted on a thumb loop shifts the position of one electrode relative to the other. Upon application of RF voltage, the distance at which the electrodes are placed controls the amount of arcing which will occur between electrodes, when placed within a proper range. The electrodes are supplied with power from a standard RF energy source, controlled from a foot or hand switch. The insulating plug may further include metal traces disposed on the peripheral surface. When energized, these traces function as a bipolar pair of electrodes for effecting electrocoagulation of tissue and blood. The instrument is for insertion in laparoscopic trocar or endoscope for trimming small polyps from wall of colon and removal of tissue, and coagulating particular vascular tissue areas.
U.S. Pat. No. 5,342,357 has a cauterization system with a radio frequency energy source including a control unit connected to the energy source, and an electrosurgical probe. The probe has a handle with an elongate member extending from the handle. The distal end of the elongate member is tapered and includes a cauterization tip and a retractable cutting electrode. The probe includes a conduit for the transmission of cooling fluid to the distal end. The temperature of the electrode on the distal end of the probe is monitored and is used to control the rate of flow of the cooling fluid to the tip. A generator supplies electrical energy to the electrodes and the impedance of the tissue between the electrode is monitored to prevent tissue damage due to high temperatures. The system controls transfer of heat to tissue during surgery and prevents tissue or coagulant from welding to energy delivering electrode.
None of the aforementioned equipment has offered the surgeon the level of control needed to remodel and reform the tissue with electrosurgical energy. No mechanism for the application of clamping pressure, electrosurgical energy and temperature to seal and/or join vascularized tissue has been found. The tissue of the patient includes collagen which has been found to bind an injury or wound, surgical or otherwise, when subject to adequate pressure and temperature. Collagen can be melted and resolidified into a load resistant natural tissue coagulant so the reformed structure is capable of enduring loads similar to that carried by uncut tissue. No mechanism for the adequate and proper application of temperature and pressure is known.
A related patent application entitled "Energy Delivery System for Vessel Sealing", attorney docket number PC 9202, has been filed concurrently with this application.